The invention relates to telecommunication networks in general and performance management of a network element in particular.
A telecommunication network typically includes a Network Management Station (NMS), and one or more Network Elements (NEs) each having a dedicated logical Management Information Base (MIB) resident therein for configuration, control and monitoring purposes. One aspect of an NE""s MOB is employed for performance management purposes in particular, including the monitoring and correcting the behavior and effectiveness of a to telecommunication network, and an NE, and to aid in planning and analysis.
In a document entitled xe2x80x9cM4 Interface Requirements and Logical MIB: ATM Network Element Viewxe2x80x94AF-NM-0020.001xe2x80x9d dated October 1998, and published by the ATM Forum Technical Committee, Section 2.3 entitled Performance Management stipulates eleven Performance Management (PM) managed entities for network data collection purposes divided into four PM Groups as shown in FIG. 1: First, an ATM PM Group including an ATM Cell Protocol Monitoring Current Data managed entity having four PM Counter attributes, and an TC Adapter Protocol Monitoring Current Data managed entity including a single PM Counter attribute. Second, an DS3/E3 PM Group including an DS3/E3 Current managed entity having ten PM Counter attributes, an DS3 Far End Current managed entity having four PM Counter attributes, and an ATM DS3 PLCP Protocol Monitoring Current Data managed entity having two PM Counter attributes. Third, an SONET/SDH PM Group including an SONET/SDH Section Current Table managed entity, an SONET/SDH Line Current Table managed entity, an SONET/SDH Far End Line Current Table managed entity, an SONET/SDH Path Current Table managed entity, and an SONET/SDH Far End Path Current Table managed entity each having four PM Counter attributes. And lastly, an VPL-TP PM Group including an UPC/NPC Disagreement Monitoring Current Data managed entity having four PM Counter attributes per VPL termination point, This document fiber stipulates that each PM Group managed entity sends an autonomous notification of a threshold crossing alert (TCA) to an NMS when one of its PM Counter attributes exceeds its pre-set threshold value, the notification including the ID of the instances of the PM Counter managed entity reporting the TCA and their actual values.
In a proposed SNMP implementation of the above referenced ATM Forum document numbered AF-NM-0095.001 in IETF""s RFC 1451-SNMPv2 M2M MIB, the TCA autonomous notification requirement was met by providing each instance of PM Group managed entity with one or more instances of PM Counter managed entities as appropriate, and each instance of an PM Counter managed entity with a Threshold Data ID attribute pointing to an instance of a Threshold Data managed entity which contains its threshold value (see FIG. 2). In accordance with SNMP practice, each instance of an PM Counter managed entity is allocated a row in a table which defines all the threshold values for all the instances of a MIB""s PM counters such that the total number of rows in the table equals the total number of a MIB""s PM counter instances as a function of both datastream types, for example, ATM over DS3, ATM over SDH STM1, and the like, and their respective quantities.
This approach for assignment of threshold values to PM counters has the advantage of maximum granularity, namely, the threshold value of each PM counter can be individually customized but the downside is that the approach quickly becomes unwieldly for even a relatively simple NE as will be readily appreciated from the following example. An exemplary NE having 3 Network Interface Cards (NICs) respectively supporting eight ATM over DS3 datastreams whose different transport levels are each policed by 5 ATM PM counters and 16 DS3/E3 PM counters, four ATM over SDH STM1 datastrems whose different transport levels are each policed by 5 ATM PM counters and 20 SONET/SDH PM counters, and a single ATM over SDH STM4 data stream whose different transport levels are policed by 5 ATM PM counters and 20 SONET/SDH PM counters, and each card having 512 Virtual Path Links Termination Points (VPL-TPs) equally divided between its datastreams and each requiring four PM counters per VPL-TP requires a table of a total of (((8*5)+(8*16)+(512*4))+((4*5)+(4*20)+(512*4))+((1*5)+(1*20)+(512*4)))=6437 rows.
In accordance with the present invention, there is provided for use with is a Network Element (NE) in a telecommunication network, the NE having a logical Management Information Base (MIB) resident therein, the MIB comprising:
(a) one or more Performance Management (PM) Group managed entities each having at least one PM Counter attribute, and a pointer; and
(b) a Threshold Crossing Alert (TCA) profile managed entity, each instance thereof having at least one PM Counter attribute, and an associated threshold value,
where an instance of an PM Group managed entity points to an instance of said TCA profile managed entity whose said at least one PM Counter attribute match those of said PM Group managed entity instance whereupon each of whose said at least one PM Counter attribute is correspondingly assigned a threshold value from said TCA profile managed entity instance.
The present invention is based on the notion that threshold values for PM counters should be assigned per instance of an PM Group managed entity for TCA autonomous notification purposes as stipulated inter alia by the ATM Forum""s AF-NM-0095.001 document as opposed to per instance of an PM Counter managed entity in accordance with the above-mentioned IETF""s RFC 1451-SNMPv2 M2M MIB. The benefits of the present invention are particularly realized when updating an NE in terms of the datastreams terminating thereat, and even more so when updating threshold values of PM counters, and to a lesser extent during telecommunication network set-up, and NE initialization. Moreover, the present invention is particularly beneficial for NEs supporting homogeneous datastreams, and can be readily augmented to existing MIBs as required by the industry. And finally, the same assignment granularity can be theoretically obtained as in IETF""s RFC 1451-SNMPv2 M2M MIB if the number of instances of the TCA profile managed entity equals the number of instances of an PM Group managed entity, however, typically far fewer TCA profile managed entity instances are required in practice.